public void test_constructor_withValidInputs() {
        CharMappingItem item = new CharMappingItem(1L, new String[] { "input" }, "output");

        // Test basic properties that exist
        assertNotNull(item.getInputs());
        assertEquals(1, item.getInputs().length);
        assertEquals("input", item.getInputs()[0]);
        assertEquals("output", item.getOutput());
    }

    public void test_constructor_withIdZero() {

                generator.saveImage(input, outputFile);
            }
            assertImageSize(outputFile, 100, 100);

            imagePath = "thumbnail/400x400.gif";
            try (ImageInputStream input = ImageIO.createImageInputStream(classLoader.getResourceAsStream(imagePath))) {
                generator.saveImage(input, outputFile);

  private static void testReverse(double[] input, double[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Doubles.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(
      double[] input, int fromIndex, int toIndex, double[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Doubles.reverse(input, fromIndex, toIndex);

  private static void testReverse(float[] input, float[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Floats.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(
      float[] input, int fromIndex, int toIndex, float[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Floats.reverse(input, fromIndex, toIndex);

  private static void testReverse(float[] input, float[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Floats.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(
      float[] input, int fromIndex, int toIndex, float[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Floats.reverse(input, fromIndex, toIndex);

  }

  private static void testReverse(long[] input, long[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Longs.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(long[] input, int fromIndex, int toIndex, long[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Longs.reverse(input, fromIndex, toIndex);

  private static void testReverse(short[] input, short[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Shorts.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(
      short[] input, int fromIndex, int toIndex, short[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Shorts.reverse(input, fromIndex, toIndex);

  private static void testReverse(double[] input, double[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Doubles.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(
      double[] input, int fromIndex, int toIndex, double[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Doubles.reverse(input, fromIndex, toIndex);

     *
     * @param input the input object (String[], List, or String)
     * @return joined string with elements separated by spaces, or empty string if invalid input
     */
    public static String join(final Object input) {
        String[] values = null;
        if (input instanceof String[]) {
            values = (String[]) input;
        } else if (input instanceof List) {

  }

  private static void testSortDescending(byte[] input, byte[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    SignedBytes.sortDescending(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testSortDescending(
      byte[] input, int fromIndex, int toIndex, byte[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);